193. Let's Look How Modern Ransomware Gangs Collect and Exfiltrate Data

Hello everyone!

Modern ransomware attack lifecycle almost always includes data collection and exfiltration stage. Some gangs don't even deploy ransomware, they just exfiltrate sensitive data and use it for extortion. 

What's more. The threat actors often use absolutely legitimate tools! Let's look at an example. SafePay ransomware.

According to the report, the adversary leveraged WinRAR for collection:

WinRAR.exe  a -v5g -ed -r -tn1000d -m0 -mt5 -x*.rar -x*.JPEG -x*.RAW -x*.PSD -x*.TIFF -x*.BMP -x*.GIF -x*.JPG -x*.MOV -x*.pst -x*.FIT -x*.FIL -x*.mp4 -x*.avi -x*.mov -x*.mdb -x*.iso -x*.exe -x*.dll -x*.bak -x*.msg -x*.png -x*.zip -x*.ai -x*.7z -x*.DPM -x*.log -x*.dxf -x*.insp -x*.upd -x*.db -x*.dwg -x*.nc1 -x*.metadata -x*.dg -x*.inp -x*.dat -x*.TIFF -x*.tiger -x*.pcp -x*.rvt -x*.rws -x*.nwc -x*.tif -x*.frx -x*.dyf -x*.rcs -x*.diff C:\[redacted].rar \\[redacted]\C$\Users\

It's interesting that in this case the adversary desided to exclude not interesting files, for example, *.exe and *.dll. Of cousre, we can use it for detection and hunting:

event_type: "processcreatewin"

AND

proc_file_originalfilename: "winrar.exe"

AND

cmdline: (*exe AND *dll)

To exfiltrated data, the threat actors used another legitimate tool -  FileZilla. This one may also be a good candidate for hunting!

See you tomorrow! 

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